Image processing apparatus

ABSTRACT

An image processing apparatus capable of reading an image recorded on a first surface and a second surface of a sheet, the image processing apparatus comprising a conveying path comprising a first conveying path formed in a substantially plate shape, a second conveying path disposed below the first conveying path and a curved conveying path disposed between the first conveying path and the second conveying path, a conveying mechanism configured to convey the sheet along a conveying direction from the first conveying path to the second conveying path through the curved conveying path, a first image reading section disposed below the first conveying path and comprising a first image sensor which reads the image recorded on the first surface of the sheet conveyed along the first conveying path at a first image reading position, a second image reading section comprising a second image sensor which reads the image recorded on the second surface of the sheet conveyed along the second conveying path from below the second conveying path at a second image reading position, and an upper cover configured to rotate between a closed position where the first conveying path is partly covered and an open position where the first conveying path is exposed, wherein at least the first conveying path is exposed when the upper cover is in the open position.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent ApplicationNo. 2009-088247, which was filed on Mar. 31, 2009, the disclosure ofwhich is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing apparatus thatreads an image recorded on both front and back surfaces of a sheetconveyed by a plurality of rollers.

2. Description of the Related Art

Conventionally, an image processing apparatus comprising a U-turnconveying path and two image reading portions is known. In such an imageprocessing apparatus, an image of one of the front and back surfaces ofthe sheet is read by one image reading portion first, and after thefront and back surfaces of the sheet is reversed, an image of another ofthe front and back surfaces of the sheet is read by another imagereading portion.

SUMMARY OF THE INVENTION

In such an image processing apparatus comprising such a U-turn conveyingpath, a plurality of rotary shafts are disposed in the U-turn conveyingpath, a conveying roller is mounted on each of the rotary shafts, andeach of the conveying rollers is paired with a pinch roller. When thesheet is nipped and conveyed by the conveying rollers and the pinchrollers, a jamming of the sheet may occur.

A need has arisen to provide an image processing apparatus that ajamming prevention operation can be easily carried out while beingcompact.

In an embodiment of the invention, an image processing apparatus capableof reading an image recorded on a first surface and a second surface ofa sheet, the image processing apparatus comprising a conveying pathcomprising a first conveying path formed in a substantially plate shape,a second conveying path disposed below the first conveying path and acurved conveying path disposed between the first conveying path and thesecond conveying path, a conveying mechanism configured to convey thesheet along a conveying direction from the first conveying path to thesecond conveying path through the curved conveying path, a first imagereading section disposed below the first conveying path and comprising afirst image sensor which reads the image recorded on the first surfaceof the sheet conveyed along the first conveying path at a first imagereading position, a second image reading section comprising a secondimage sensor which reads the image recorded on the second surface of thesheet conveyed along the second conveying path from below the secondconveying path at a second image reading position, and an upper coverconfigured to rotate between a closed position where the first conveyingpath is partly covered and an open position where the first conveyingpath is exposed, wherein at least the first conveying path is exposedwhen the upper cover is in the open position.

According to the present invention, an image recorded on both front andback surfaces of a sheet can be read without using a reverse conveyingpath. Moreover, since the upper cover can rotate between the closedposition and the open position, a jamming prevention operation can beeasily carried out while being compact.

Other objects, features, and advantages of embodiments of the presentinvention will be apparent to persons of ordinary skill in the art fromthe following description of preferred embodiments with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an image processing apparatus accordingto an embodiment of the present invention.

FIG. 2 is a perspective view of the image processing apparatus accordingto the embodiment of the present invention.

FIG. 3 is a perspective view of the image processing apparatus accordingto the embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1.

FIG. 5 is a sectional view of the image processing apparatus accordingto the embodiment of the present invention.

FIG. 6 is an enlarged view of the main portion in FIG. 4.

FIG. 7 is a layout of a driving system of the image processing apparatusaccording to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will hereunder be described in detail on the basisof preferred embodiments with reference to the drawings as required.

[General Structure of Image Processing Apparatus]

FIG. 1 is a perspective view of an image processing apparatus 10according to an embodiment of the present invention.

The image processing apparatus 10 includes an image reading device 20,an automatic document feeder (ADF) 11 disposed at the upper portion ofthe image reading device 20, and an operation panel 40 provided at thefront side of the image reading device 20. The ADF 11 is rotatablyprovided with respect to the image reading device 20. Therefore, the ADF11 can be used to open and close the upper side of the image readingdevice 20 (see FIG. 2). When a user perform a reading operation withoutusing the ADF 11, the user opens the ADF 11 and place original sheets ona predetermined position on an after-mentioned moving reading glass 80.Then, the user closes the ADF 11 and operates the operation panel 40,and thereby can read an image of an original sheet placed on the movingreading glass 80.

FIG. 2 is a perspective view of the image processing apparatus 10 in astate in which the ADF 11 is open with respect to the image readingdevice 20. Actually, a white original pressing plate is disposed on asurface opposing almost whole surface of the moving reading glass 80 ofa lower surface 31 of a body frame 30 of the ADF 11, but the originalpressing plate is omitted in FIG. 2. FIG. 3 is a perspective view of theimage processing apparatus 10 in a state in which an upper cover 32 (anexample of an upper cover according to the present invention) of the ADF11 is open. FIG. 4 is a sectional view taken along line IV-IV in FIG. 1.

The ADF 11 is disposed so as to cover the upper side of the imagereading device 20, and can change its position between a “closedposition” shown in FIG. 1 and an “open position” shown in FIG. 2, asmentioned above. As shown in FIGS. 3 and 4, the ADF 11 includes anoriginal tray 12 (an example of a feed tray according to the presentinvention) on which original sheets are placed, and a sheet-dischargetray 14 to which the original sheets are discharged. The original tray12 and the sheet-discharge tray 14 are disposed vertically in twolevels. More specifically, the original tray 12 is disposed above thesheet-discharge tray 14. In the embodiment, the sheet-discharge tray 14has a recessed portion formed in the body frame 30 of the ADF 11.

The ADF 11 conveys an original sheet drawn out from the original tray 12along a U-turn conveying path 16 (an example of a conveying path, aconveying path according to the present invention), and discharges theoriginal sheet to the sheet-discharge tray 14. The original tray 12 canhold a plurality of original sheets in a stacked state. In a case thatimages are recorded on both a front surface and a back surface of theoriginal sheet, the original sheets are held in the stacked state inorder of a first page as an uppermost surface, a third page, a fifthpage, and so on, that is, odd pages face upward. Even pages are backsurfaces of the odd pages and face downward. The ADF 11 continuouslytakes out the original sheets held in the stacked state one at a timefrom the original tray 12. The original sheets taken out from theoriginal tray 12 are oriented in a direction toward the sheet-dischargetray 14 along the U-turn conveying path 16 (that is, a conveyingdirection), and are automatically conveyed to the sheet-discharge tray14. The ADF 11 also includes an image sensor 24. As shown in FIG. 4,when the original sheet is conveyed along the conveying path 16, theimage sensor 24 reads an image recorded on a first surface (backsurface) of the original sheet. For the image sensor 24, a contact imagesensor (CIS) or a charged coupled device (CCD) can be typically used,but in this embodiment the image sensor 24 is a CIS. By using a CIS asthe image sensor 24, the image sensor 24 can be downsized, and the ADF11, eventually, the image processing apparatus 10 can be downsized.

The image reading device 20 includes a contact glass 22. The contactglass 22 is disposed at the upper surface of the image reading device20. An image sensor 25 is provided below the contact glass 22. Whenconveying the original sheet along the U-turn conveying path 16, theimage sensor 25 reads an image recorded on a second surface (frontsurface) of the original sheet. The image sensor 25 also can read theimage on the original sheet placed on the moving reading glass 80 whilemoving along an after-mentioned slide shaft 78. For the image sensor 25,a CIS or a CCD is also typically used, but in this embodiment the imagesensor 25 is also a CIS. The image reading device 20 may have anystructure as long as the ADF 11 is applicable. But, by using a CIS asthe image sensor 25, the image sensor 25 can be downsized, and the imagereading device 20, eventually, the image processing apparatus 10 can bedownsized.

The embodiment exemplifies the case in which the present invention iscarried out by using the image reading device 20 and the ADF 11applicable thereto. However, the present invention may be carried out byusing a copier or a multi-function device (MFD) which is mounted on topof an image recording device that records an image by adhering an imagerecording material (such as toner or ink) to a recording sheet.

[U-Turn Conveying Path]

As shown in FIG. 4, the U-turn conveying path 16 includes a firstconveying path 26 (an example of a first conveying path according to thepresent invention), a curved conveying path 27 (an example of a curvedconveying path according to the present invention), and a secondconveying path 28 (an example of a second conveying path according tothe present invention). That is, the U-turn conveying path 16 is formedin a substantially U shape so that the original sheet placed on theoriginal tray 12 is conveyed to the sheet-discharge tray 14. As shown inFIG. 4, the first conveying path 26 extends leftwards from the originaltray 12. The original sheets to be conveyed are supplied to the firstconveying path 26 by a sheet-feed unit 50 (an example of a feed unitaccording to the present invention), as mentioned later. In thisembodiment, more specifically, as shown in FIG. 6, the first conveyingpath 26 is a conveying path from a left side of after-mentionedconveying roller 61 and pinch roller 65 to a nip point ofafter-mentioned main roller 64 and pinch roller 62. A range of the firstconveying path 26 is indicated by an arrow 26A. The first conveying path26 is formed in a substantially plate shape, as shown in FIGS. 3 and 6.The first conveying path 26 includes an image reading position 19 (anexample of a first image reading position according to the presentinvention) where the image sensor 24 reads the first surface of theoriginal sheet.

The curved conveying path 27 is connected with the first conveying path26, and is curved downward in an arc shape. More specifically, as shownin FIG. 6, the curved conveying path 27 is a conveying path from a nippoint of after-mentioned main roller 64 and pinch roller 62 to anafter-mentioned opening 84. A range of the curved conveying path 27 isindicated by an arrow 27A.

The second conveying path 28 is connected with the curved conveying path27, and extends to the upper right in the figure toward thesheet-discharge tray 14 in FIGS. 4 and 6. More specifically, as shown inFIG. 6, the second conveying path 28 is a conveying path from anafter-mentioned opening 84 to a left side of an after-mentioneddischarge unit 70 (a discharge roller 72 and a pinch roller 74). A rangeof the second conveying path 28 is indicated by an arrow 28A. The secondconveying path 28 includes an image reading position 21 (an example of asecond image reading position according to the present invention) wherethe image sensor 25 reads the second surface of the original sheet.

The ADF 11 includes a housing. This housing includes a body frame 30,the aforementioned upper cover 32, an upper guide 34, and an under guide36. The upper cover 32, the upper guide 34, and the under guide 36 aremounted to the body frame 30. The housing is formed ofacrylonitrile-butadiene-styrene (ABS) copolymer, polypropylene (PP),polyacetal (POM), or other types of synthetic resins.

The upper guide 34 and the under guide 36 are disposed vertically in twolevels. By mounting the under guide 36 to the body frame 30, the secondconveying path 28 is formed between the body frame 30 and the underguide 36. That is, the under guide 36 forms a guide surface of thesecond conveying path 28. The upper guide 34 is mounted above the underguide 36. As shown in FIGS. 2 and 4, an opening 84 is provided in alower surface 31 of the ADF 11. The opening 84 is provided at an endsituated at a boundary portion between the second conveying path 28 andthe curved conveying path 27. By providing the opening 84, the boundaryportion between the second conveying path 28 and the curved conveyingpath 27 is exposed to the lower surface of the ADF 11. The opening 84 ispositioned across a width indicated by an arrow 85. An after-mentionedpredetermined position 18 is included in a range of the opening 84.Therefore, when the image sensor 25 is disposed in the predeterminedposition 18, the image sensor 25 can read the front surface of theoriginal sheet at the image reading position 21.

FIG. 5 is a sectional view of the image processing apparatus 10 which istaken along line IV-IV in FIG. 1, like FIG. 4. But FIG. 5 shows theimage processing apparatus 10 in a state in which the aforementionedupper cover 32 is open, unlike FIG. 4.

The upper cover 32 is rotatably supported by a support shaft 15 mountedto the left end (in FIG. 5) of the body frame 30, and can be opened andclosed. That is, the upper cover 32 can change its position between aclosed position (shown in FIG. 4) and an open position (shown in FIG.5). When the upper cover 32 is in the closed position, as shown in FIG.4, a portion extending from the first conveying path 26 to the upperguide 34 is covered by the upper cover 32. A portion of the curvedconveying path 27, the sheet-feed unit 50, the conveying roller 61, thepinch roller 65 and a portion of the original tray 12 are also coveredby the upper cover 32.

When the upper cover 32 is in the closed position, as shown in FIG. 6,the first conveying path 26 is formed between the upper cover 32 and theupper guide 34. That is, the upper cover 32 partly forms a guide surfaceof the first conveying path 26.

As shown in FIG. 5, when the position of the upper cover 32 changes tothe open position, the portion extending from the first conveying path26 to the upper guide 34 is exposed. A portion of the curved conveyingpath 27, the sheet-feed unit 50, the conveying roller 61, the pinchroller 65 and a portion of the original tray 12 are also exposed. Asshown in FIGS. 3 and 5, the pinch roller 62 and a first white member 76are positioned on the upper cover 32. More specifically, a rotary shaft62A of the pinch roller 62 is supported by the upper cover 32 (see FIG.3). The first white member 76 is supported by the upper cover 32 via acoil spring 77. Therefore, when the position of the upper cover 32changes to the open position, all the first conveying path 26 and aportion of the curved conveying path 27 are exposed. As a result, when ajamming of the original sheet occurs, the user can easily carry out ajamming prevention operation by changing the position of the upper cover32 to the open position.

[Sheet-Feed Unit]

FIG. 6 is an enlarged view of the main portion in FIG. 4, and shows indetail the U-turn conveying path 16 and the vicinity thereof.

As shown in FIGS. 4 and 6, a sheet-feed unit 50 is disposed adjacent tothe first conveying path 26. The sheet-feed unit 50 sequentially takesout the original sheets held in the stacked state one at a time in orderfrom top from the original tray 12. The sheet-feed unit 50 is providedupstream of the first conveying path 26 in the conveying direction (thatis, at the right side in FIGS. 4 and 6). The sheet-feed unit 50 includesa take-in roller 52 and a separation roller 54 having a rotary shaft 56.As is clear from FIG. 3, both ends of the rotary shaft 56 are supportedby the body frame 30. The separation roller 54 is secured to the almostcenter of the rotary shaft 56. The rotary shaft 56 is rotated in apredetermined direction (clockwise in FIG. 4) by an ADF motor (notshown) serving as a driving source. The separation roller 54 is rotatedby rotating the rotary shaft 56.

An arm 58 is supported by the rotary shaft 56 through a bearing. The arm58 extends toward upstream in the conveying direction from the rotaryshaft 56. The take-in roller 52 is disposed an end upstream of the arm58 in the conveying direction. The arm 58 is rotated through apredetermined driving transmission mechanism (not shown) by using theADF motor serving as the driving source. Therefore, the arm 58 can moveup and down with respect to the rotary shaft 56 as center. The take-inroller 52 is also connected to the rotary shaft 56 through apredetermined driving transmission mechanism. By this, if the rotaryshaft 56 rotates, not only the separation roller 54, but also thetake-in roller 52 rotates clockwise. The outside diameter of the take-inroller 52 and the outside diameter of the separation roller 54 are setthe same, so that both of the rollers 52 and 54 are rotated at the sameperipheral speed.

The sheet-feed unit 50 also includes a separation portion 57. Theseparation portion 57 is disposed so as to oppose the separation roller54. The separation portion 57 is configured to press-contact the rollersurface of the separation roller 54. The separation portion 57 istypically formed of a cork piece or an elastomer, and provides a largefriction force between it and an original sheet. Therefore, if aplurality of original sheets are inserted between the separation portion57 and the separation roller 54, at a nip point 89 (see FIG. 7) of theseparation roller 54, only the original sheet that is in contact withthe separation roller 54 is separated from other original sheets andconveyed toward the U-turn conveying path 16.

A plurality of original sheets in a stacked state are placed on theoriginal tray 12. At this time, an original sheet is place in a statethat an end of each original sheet is inserted into the sheet-feed unit50. Furthermore, at this time, the original sheets are placed on theoriginal tray 12 with the front surface (a surface of odd pages, anupper surface, a second surface) faced upward. An image recorded on theback surface (a surface of even pages, a lower surface, a first surface)of the original sheet taken out from the original tray 12 by the ADF 11is read by the image sensor 24. The original sheet is further conveyedalong the U-turn conveying path 16, and its front and back surfaces arereversed when the original sheet passes along the curved conveying path27. Then, an image recorded on the front surface of the original sheetis read by the image sensor 25. Thereafter, the original sheetdischarged to the sheet-discharge tray 14 has its front surface faceddownward and is placed on the sheet-discharge tray 14. Therefore, evenif a plurality of the original sheet are conveyed by the ADF 11 to readthe image thereon, an order of the page of the original sheets will notbe changed from a case that the original sheets are placed on theoriginal tray 12 to a case that the original sheets are stacked on thedischarge tray 14, though the original sheets will be turned upsidedown.

[Conveying Unit]

As shown in FIG. 6, a conveying unit 60 (an example of a conveyingmechanism according to the present invention) includes a conveyingroller 61 (a first conveying roller), a main roller 64 (an example of adriving roller according to the present invention), a pinch roller 62(second conveying roller), and a pinch roller 63 (third conveyingroller).

The conveying roller 61 is disposed adjacent to the first conveying path26. More specifically, the conveying roller 61 is disposed immediatelyin front of the first conveying path 26 in the conveying direction, andis positioned more downstream in the conveying direction than theseparation roller 54. The conveying roller 61 form a pair of rollerswith the pinch roller 65 (an example of a pair of conveying rollersaccording to the present invention). The original sheet conveyed fromthe separation roller 54 is nipped by the conveying roller 61 and thepinch roller 65. The conveying roller 61 rotates to supply the originalsheet to the first conveying path 26.

As shown in FIG. 6, the main roller 64 is disposed at an end portion(left end portion in FIG. 6) of the body frame 30. The body frame 30,the upper cover 32 of the ADF 11, and the main roller 64 form the curvedconveying path 27. That is, the body frame 30, an inner wall surface ofthe upper cover 32, and the outer peripheral surface of the main roller64 form a guide surface of the curved conveying path 27. As is clearfrom FIG. 3, the main roller 64 comprises three rollers that aresupported by only one driving shaft 67 (an example of a driving shaftaccording to the present invention) and are disposed at a predeterminedinterval. The central main roller 64 of the three main rollers 64 formsa pair of rollers with the pinch roller 62 (an example of a pinch rolleraccording to the present invention), and a pair of rollers with thepinch roller 63 (an example of a pinch roller according to the presentinvention). The pinch roller 62 is disposed at a boundary between thefirst conveying path 26 and the curved conveying path 27 as mentionedabove. The original sheet conveyed along the first conveying path 26 isnipped by the main roller 64 and the pinch roller 62, and is conveyedalong the curved conveying path 27 in the conveying direction. The pinchroller 63 is disposed downstream of the curved conveying path 27 in theconveying direction. The original sheet conveyed along the curvedconveying path 27 is nipped by the main roller 64 and the pinch roller63, and is conveyed toward the second conveying path 28. Although, inthe embodiment, the main roller 64 comprising only one driving shaft 67forms pairs of rollers with the pinch rollers 62 and 63, a plurality ofdriving rollers that form pairs with these rollers 62 and 63,respectively, may be provided along the curved conveying path 27. Thisis a configuration in which the plurality of the driving rollers eachcomprising a driving shaft are provided along the curved conveying path27, a pinch roller is provided on each of the plurality of the drivingrollers. The configuration of this embodiment, in which the main roller64 comprising only one driving shaft 67 forms pairs of rollers with thepinch rollers 62 and 63, can realize reduction of configuration anddownsizing by reducing the number of the driving rollers and a drivemechanism. At a position along the curved conveying path 27 between thepinch rollers 62 and 63, other pinch roller may be provided to press themain roller 64.

The conveying roller 61 and the main roller 64 include driving shafts 66and 67, respectively. These driving shafts 66 and 67 are driven througha predetermined driving transmission mechanism by the ADF motor (notshown) as the driving source. By this, the original sheet is conveyed inthe conveying direction along the first conveying path 26 and the curvedconveying path 27.

[Discharge Unit]

As shown in FIG. 6, a discharge unit 70 includes a discharge roller 72and a pinch roller 74. The discharge roller 72 includes a driving shaft71. The driving shaft 71 is driven through a predetermined drivingtransmission mechanism by the ADF motor serving as the driving source.The discharge roller 72 is disposed immediately behind the secondconveying path 28 in the conveying direction. The discharge roller 72and the pinch roller 74 nip the original sheet conveyed along the secondconveying path 28, and convey it in the conveying direction. Since thesecond conveying path 28 extends obliquely upward as mentioned above,the discharge roller 72 is positioned above the sheet-discharge tray 14.Therefore, the original sheet that passes the discharge roller 72 andthat is discharged falls onto the sheet-discharge tray 14. Furthermore,since the discharge unit 70 is disposed below the sheet-feed unit 50,more specifically below the take-in roller 52, the second conveying path28 is longer than the first conveying path 26, as shown by arrows 26Aand 28A in FIG. 6. Therefore, even if an angle that the second conveyingpath 28 slants obliquely upward is not so large, that is, even if thesecond conveying path 28 has a gentle slant, an after-mentioned liftamount 88 can be large. As a result, a large amount of the originalsheets can be held on the discharge tray 14, while a height of the ADF11 can be downsized vertically.

The discharge roller 72 and the pinch roller 74 may not be disposedimmediately behind the second conveying path 28 in the conveyingdirection. If the original sheet can be guided from the second conveyingpath 28 to the discharge tray 14, the discharge roller 72 and the pinchroller 74 may be disposed in the second conveying path 28 in theconveying direction.

[First Image Reading Section]

As mentioned above, the first image reading section (an example of afirst image reading section according to the present invention) isprovided at the ADF 11. The first image reading section comprises animage sensor 24 (an example of a first image sensor according to thepresent invention), a first image reading glass 75 (an example of afirst platen according to the present invention), a first white member76 (an example of a first pressing member according to the presentinvention) and a coil spring 77 (an example of a first urging memberaccording to the present invention). The first image reading glass 75 istabular and a surface of the first image reading glass 75 is disposedalong the substantially planate first conveying path 26. The first imagereading glass is disposed between the conveying roller 61 and the pinchroller 62, and the image sensor 24 is provided so as to face the firstconveying path 26 from below via the first image reading glass 75. Theimage sensor 24 is disposed in space enclosed with the first conveyingpath 26, the main roller 64 and the second conveying path 28. Therefore,the original sheet that is conveyed along the substantially planatefirst conveying path 26 passes near the image sensor 24 along the firstimage reading glass 75. Here, an image recorded on the back surface(first surface) of the original sheet is read at the image readingposition 19 by the image sensor 24. The first white member 76 isdisposed so as to oppose the image sensor 24 via the first image readingglass 75. As shown in FIG. 3, the first white member 76 has almost thesame length as the first image reading glass 75 in a longitudinaldirection. A coil spring 77 is provided at the first white member 76. Bythis, the first white member 76 is resiliently urged toward the firstimage reading glass 75, that is, the image sensor 24. Therefore, thefirst white member 76 pushes the original sheet that is conveyed alongthe first conveying path 26 against the first image reading glass 75. Asa result, a distance between the image sensor 24 and the back surface ofthe original sheet becomes constant, and a good image reading operationcan be performed by a CIS whose depth of focus is smaller than a CCD. Atleast a surface of the first white member 76 that faces the first imagereading glass 75 is white in color. By this, at a predetermined timingbefore reading an image, a processing of taking a white standard whenthe image sensor 24 reads an image is performed, but the processing isknown and is not described here.

As mentioned above, the configuration of this embodiment, in which aplurality of the pinch rollers 62 and 63 are pressed against the mainroller 64 comprising only one driving shaft 67, can realize reduction ofconfiguration and downsizing by reducing the number of the drivingrollers and a drive mechanism. But in this case the first image readingsection needs to be disposed on the substantially planate firstconveying path 26.

If the first image reading section is disposed downstream of the opening84 of the second conveying path 28 in the conveying direction, a jammingprevention operation becomes more difficult, and the sheet-feed unit 50,the conveying roller 61 and the pinch roller 65 will be disposed abovethe first image reading section. By this, the image processing apparatus10 will be larger vertically in size.

The first white member 76 of this embodiment is made of a sheetedmember, but may be made of a rotary roller with a white surface instead.In this case, the rotary roller may have almost the same length as thefirst image reading glass 75 in a longitudinal direction and may bedisposed so as to contact the first image reading glass 75 at the firstimage reading position 19. In this case, the rotary roller may beresiliently urged toward the first image reading glass 75, that is, theimage sensor 24, by an urging member such as the coil spring 77.

[Second Image Reading Section]

As mentioned above, the second image reading section (an example of asecond image reading section according to the present invention) isprovided at a side of the image reading device 20. The second imagereading section comprises an image sensor 25 (an example of a secondimage sensor according to the present invention), a stationary readingglass 79, a second white member 82 and a coil spring 83. The imagesensor 25 is slidably supported by a slide shaft 78. The slide shaft 78is secured to a housing of the image reading device 20, and extends inthe illustrated left-right direction as shown in FIGS. 4 and 6. That is,the slide shaft 78 extends in the original-sheet conveying direction andin a direction opposite thereto. The image sensor 25 slides through apredetermined driving transmission mechanism by a motor (not shown) as adriving source. An example of the driving transmission mechanism in thiscase is a pulley-belt mechanism.

The contact glass 22 of the image reading device 20 is divided in two.That is, the contact glass 22 includes a stationary reading glass 79 anda moving reading glass 80. When the ADF 11 is not used, original sheetsare placed at a predetermined position on the moving reading glass 80one at a time by the user of the image processing apparatus. Then,images that are recorded on the original sheets facing the movingreading glass 80 are read while sliding the image sensor 25 along theslide shaft 78.

When the ADF 11 is used, the original sheets continuously pass thestationary reading glass 79. An original separation member 81 isprovided between the stationary reading glass 79 and the moving readingglass 80. The original separation member 81 takes up from the stationaryreading glass 79 the original sheet that has entered the secondconveying path 28 and that has contacted the stationary reading glass79. This causes the original sheet to separate from the stationaryreading glass 79 and to be conveyed along the second conveying path 28.

When the ADF 11 is used, the image sensor 25 is moved to a predeterminedposition 18 and is stopped. By stopping the image sensor 25 at thepredetermined position 18, the image sensor 25 is provided so as to facethe second conveying path 28 from below via the stationary reading glass79. The predetermined position 18 is situated at an end portion of thestationary reading glass 79 and adjacent to the original separationmember 81. The original sheet is conveyed between the stationary readingglass 79 and the second white member 82 and reaches an actual imagereading position 21, and is, then, taken up from the stationary readingglass 79 by the original separation member 81. The original sheet isalways exposed from the opening 84 when it passes the image readingposition 21. That is, an image that has been recorded on the frontsurface of the original sheet is exposed from the opening 84. The imagesensor 25 in a standby state at the predetermined position 18 reads theexposed image at the image reading position 21.

A second white member 82 is disposed at a position corresponding to theimage reading position 21. As shown in FIG. 2, the second white member82 has almost the same length as the stationary reading glass 79 in alongitudinal direction. More specifically, the second white member 82 isprovided at the under guide 36 of the ADF 11 via the coil spring 83. Thesecond white member 82 faces the image sensor 25 in the standby state atthe predetermined position 18 via the stationary reading glass 79.Therefore, the second white member 82 is resiliently urged toward thestationary reading glass 79, that is, the image sensor 25. When an edgeof the original sheet that is conveyed along the second conveying path28 reaches the second white member 82, the original sheet moves into aspace between the second white member 82 and the stationary readingglass 79. The second white member 76 pushes the original sheet againstthe stationary reading glass 79. As a result, a distance between theimage sensor 25 and the front surface of the original sheet becomesconstant, and a good image reading operation can be performed by a CISwhose depth of focus is smaller than a CCD. At least a surface of thesecond white member 82 that faces the stationary reading glass 79 iswhite in color. By this, at a predetermined timing before reading animage, a processing of taking a white standard when the image sensor 25reads an image is performed, but the processing is known and is notdescribed here.

The second white member 82 of this embodiment is made of a sheetedmember, but may be made of a rotary roller with a white surface instead.In this case, the rotary roller may have almost the same length as thestationary reading glass 79 in a longitudinal direction and may bedisposed so as to contact the stationary reading glass 79 at the secondimage reading position 21. In this case, the rotary roller may beresiliently urged toward the stationary reading glass 79, that is, theimage sensor 25, by an urging member such as the coil spring 83.

If the configuration of this embodiment is used, the first image readingsection is disposed below (lower than) the sheet-feed unit 50. The firstwhite member 76 and the first image sensor 24 of the first image readingsection, and the second white member 82 and the coil spring 83 of thesecond image reading section are vertically disposed in space betweenthe main roller 64 comprising only one drive shaft 67 and the sheet-feedunit 50. The first white member 76 and the first image sensor 24 of thefirst image reading section, and the second white member 82 and the coilspring 83 of the second image reading section are also verticallydisposed in space between the curved conveying path 27 and thesheet-feed unit 50. As a result, the image processing apparatus 10 canbe downsized vertically.

FIG. 7 is a layout of a driving system of the ADF 11.

As shown in FIG. 7, in the ADF 11 according to the embodiment, theconveying roller 61 and the pinch roller 62 are positioned between thepinch roller 63 and the discharge roller 72. More specifically, adistance 91 between the pinch roller 63 and the discharge roller 72 isequal to the distance between a first span point P1 and a second spanpoint P2. The first span point P1 is a nip point between the pinchroller 63 and the main roller 64. The second span point P2 is a nippoint between the discharge roller 72 and the pinch roller 74. Adistance 92 between the conveying roller 61 and the pinch roller 62 isthe distance between a third span point P3 and a fourth span point P4.The third span point P3 is a nip point between the conveying roller 61and the pinch roller 65. The fourth span point P4 is a nip point betweenthe pinch roller 62 and the main roller 64. The distance 91 is greaterthan the distance 92, and the conveying roller 61 and the pinch roller62 are positioned within an imaginary area 95 formed by imaginary lines93 and 94 extending upward from the first span point P1 and the secondspan point P2, respectively.

The nip point 89 of the separation roller 54 exists within the imaginaryarea 95. However, the nip point 89 exists outside an imaginary area 98formed by an imaginary line 96 and 97 extending upward from the thirdspan point P3 and the fourth span point P4, respectively. Further, thenip point 89 is disposed closer to the second conveying path 28 than thethird span point P3, that is, below the third span point P3.

[Operation of Image Processing Apparatus]

In the image processing apparatus 10, the ADF 11 operates and conveysoriginal sheets as follows.

As shown in FIG. 6, an original sheet separated from other originalsheets on the original tray 12 by the sheet-feed unit 50 is conveyed tothe first conveying path 26 by the conveying roller 61 and the pinchroller 65. When the original sheet is conveyed along the first conveyingpath 26, an image that has been recorded on its back surface is scannedat the image reading position 19 by the image sensor 24. The originalsheet is conveyed along the curved conveying path 27 by the main roller64 and the pinch roller 62, and then is conveyed to the second conveyingpath 28 by the main roller 64 and the pinch roller 63. The originalsheet that has entered the second conveying path 28 is temporarilyexposed from the opening 84. This time, since an image of the originalsheet is scanned by the ADF 11, the image sensor 25 moves to thepredetermined position 18. Therefore, when the original sheet passes theopening 84, an image that has been recorded on the front surface of theoriginal sheet is scanned at the image reading position 19 by the imagesensor 25. Thereafter, the original sheet is discharged to thesheet-discharge tray 14 by the discharge roller 72.

Since the second conveying path 28 is tilted obliquely upward, theoriginal sheet that has been conveyed along the second conveying path 28is raised upward and, then, falls upon the sheet-discharge tray 14.Here, as shown in FIG. 8, the first distance 91 between the dischargeroller 72 and the pinch roller 63 is greater than the second distance 92between the conveying roller 61 and the pinch roller 62. Therefore, alift amount 88 of the original sheet that is conveyed along the secondconveying path 28 is large. Consequently, in the interior of the imageprocessing apparatus 10, a large area or space for stacking thedischarged original sheets upon each other is ensured. Moreover, sincethe conveying roller 61 and the pinch roller 62 are disposed in theimaginary area 95, the conveying roller 61 and the pinch roller 62 canbe disposed vertically close to the pinch roller 63 and the dischargeroller 72. That is, the conveying roller 61, the pinch roller 62, thepinch roller 63, and the discharge roller 72 are compactly disposedvertically.

Since the conveying roller 61 and the other rollers for conveying theoriginal sheet are compactly laid out vertically, a compact design ofthe image processing apparatus 10 is possible. Moreover, as mentionedabove, since a large area for stacking the discharged original sheetsupon each other is provided, the image processing apparatus 10 canhandle the required and sufficient number of original sheets while beingcompact.

In the embodiment, since the original tray 12 is disposed above thesheet-discharge tray 14, the original sheet is moved downward throughthe U-turn conveying path 16 from the original tray 12 disposed abovethe sheet-discharge tray 14, and is held by the sheet-discharge tray 14.Therefore, the user can easily take out any discharged original sheet.That is, handling of original sheets 58 is facilitated.

In the embodiment, since the conveying roller 61 is disposed close tothe first conveying path 26, the distance 91 can be made very small.Therefore, the horizontal dimension (that is, the left-right dimensionin FIG. 4) of the image processing apparatus 10 is small, so that theapparatus can be more compactly designed.

In particular, in the embodiment, the opening 84 is provided at thelower surface of the ADF 11. As mentioned above, the original sheet isexposed from the opening 84 when the image sensor 25 scans an image. Byproviding the opening 84, the user can deliberately take out theoriginal sheet from the opening 84. Therefore, if what is called ajamming prevention operation needs to be performed on the original sheetthat is being conveyed along the curved conveying path 27, the originalsheet is immediately pulled out from the opening 84. That is, thejamming prevention operation is facilitated.

In addition, in the embodiment, as shown in FIG. 8, since the nip point89 of the separation roller 54 is disposed at the aforementionedposition, the separation roller 54 and the separation portion 57 forsupplying the original sheet to the conveying roller 61 can be disposedlower than the conveying roller 61. Therefore, it is possible to makethe image processing apparatus 10 thin and compact.

In this embodiment, the image processing apparatus 10 is an imageprocessing apparatus for a two-side reading, which has a configurationin which images recorded on both sides of the original sheet are read bytwo image sensors 24 and 25. However, by using the same body frame asthe body frame 30 and reducing a part of the components, an imageprocessing apparatus for a one-side reading, in which an image recordedon one side of the original sheet is read while conveying from theoriginal tray to the discharge tray, can be inexpensively configured.This is because a part of the components is configured to be removable.In this case, for example, the image sensor 24, the conveying roller 61,the pinch roller 65, the drive shaft 66, the first image reading glass75, the first white member 76 and the coil spring 77 may be reduced. Thedrive mechanism for driving the drive shaft 66 of the conveying roller61 may be also reduced. Instead of these components, other replacementsrequired to configure the image processing apparatus for a one-sidereading may be replaced as required. That is, instead of the first whitemember 76 and the first image reading glass 75, for example, guidemembers which configure the first conveying path 26 may be replacedseparately.

What is claimed is:
 1. An image processing apparatus capable of readingan image recorded on a first surface and a second surface of a sheet,the image processing apparatus comprising: a conveying path comprising:a first conveying path formed in a substantially plate shape; a secondconveying path disposed below the first conveying path; and a curvedconveying path disposed between the first conveying path and the secondconveying path, a conveying mechanism configured to convey the sheetalong a conveying direction from the first conveying path to the secondconveying path through the curved conveying path; a first image readingsection disposed below the first conveying path and comprising a firstimage sensor which reads the image recorded on the first surface of thesheet conveyed along the first conveying path at a first image readingposition; a second image reading section comprising a second imagesensor which reads, from below the second conveying path at a secondimage reading position, the image recorded on the second surface of thesheet conveyed along the second conveying path; and an upper coverconfigured to rotate between a closed position where the first conveyingpath is partly covered and an open position where the first conveyingpath is exposed, wherein the first conveying path and the first imagesensor are exposed when the upper cover is in the open position, whereinthe first image reading section further comprises: a first platen formedin a plate shape, which is transparent and configures a part of thefirst conveying path; a first pressing member configured to press thesheet at the first image reading position on the first platen toward thefirst image sensor; and a first urging member configured to urge thefirst pressing member toward the first platen, and wherein the firstpressing member is supported by the upper cover via the first urgingmember, and the first pressing member separates from the first platenwhen the upper cover is in the open position.
 2. The image processingapparatus according to claim 1, wherein the conveying mechanismcomprises: a driving roller comprising only one drive shaft in thecurved conveying path; and at least two pinch rollers urged by thedriving roller, wherein one pinch roller of the at least two pinchrollers which is positioned upstream in the conveying direction issupported by the upper cover, and the curved conveying path is alsopartly exposed by separating the one pinch roller from the drivingroller when the upper cover is in the open position.
 3. The imageprocessing apparatus according to claim 1, wherein the conveyingmechanism comprises a pair of conveying rollers disposed upstream of thefirst conveying path in the conveying direction, wherein the imageprocessing apparatus further comprises: a feed tray disposed upstream ofthe pair of the conveying rollers in the conveying direction andconfigured to hold a plurality of sheets in a stacked state; and a feedunit configured to separate one of the plurality of the sheets held onthe feed tray and feed the separated sheet toward the pair of theconveying rollers, and wherein the upper cover covers the pair of theconveying rollers, the feed unit and a part of the feed tray when theupper cover is in the closed position, and the upper cover exposes thepair of the conveying rollers, the feed unit and a part of the feed traywhen the upper cover is in the open position.
 4. The image processingapparatus according to claim 1, wherein the first image sensor isdisposed in space enclosed with the first conveying path, the drivingroller and the second conveying path.